Fast Pretreatment Of Organophosphorous Pesticide Wastewater

A new technology of combination of ozone and high voltage pulsedcorona was developed to treat organophosphorous pesticide wastewater,Venturi mixer and pipe reactor were used to increase the mass transferefficiency and increase the removal rate of organic pollutants.The optimum experimental conditions was obtained from theexperiment of CODEr removal rate of DDVP: ozone flow was 2.48g/h,initial pH value was 9, pipe length was 5m, impulse voltage was 30kV andreaction time was 20min. Through the contrast of CODEr removal rate ofDDVP by separate treatment and by combination treatment, the synergismof corona was validated. It was found that DDVP degradation bycombination treatment followed pseudo-first-order kinetics.The experimental results also indicated that degradation rate ofdifferent pesticide decreased as fellow: DDVP＞Phoxim＞Acephate. After6min, the value of B/C increased from 0.15, 0.23, 0.30 to 0.25, 0.29, 0.40respectively. However, after 6min the value of B/C decreased with theincreasing of reaction time. According to the results of GC-MS, the possible pathway of DDVPdegradation was proposed.The value of B/C of wastewater (COD_cr=44458mg/L) fromamination section which obtained from pesticide plant of Zhejiang JiahuaGroup Co. Ltd was increased from 0.10 to 0.21 for 60min ozonation.To sum up, the combination technology of ozone and high voltagecorona had several advantages, such as high treatment efficiency, nosecondary pollution and quick degradation rate, and its required space wassmall. It could improve the biodegradability of organophosphorouspesticide wastewater, which can reduce the load of later biochemicaltreatment. So it is suitable for the pretreatment for organophosphorouspesticide wastewater with high concentration and low biodegradability.